Surface modification of titanium alloy with the Ti3Al + TiB2/TiN composite coatings

Laser cladding of the Ti3Al + TiB2 pre-placed alloy powder on the Ti–6Al–4 V alloy in nitrogen protective atmosphere can form the Ti3Al + TiB2/TiN composite coating, which can dramatically improve the wear resistance of the Ti–6Al–4 V alloy surface. In this study, the Ti3Al + TiB2/TiN composite coatings on the Ti–6Al–4 V alloy have been researched by means of X-ray diffraction, SEM and energy dispersive spectrometry. It was found that there is a metallurgical combination between the Ti3Al + TiB2/TiN composite coating and the substrate. The microhardness of the Ti3Al + TiB2/TiN composite coatings were 3 ~ 4 times higher than that of the Ti–6Al–4 V alloy because of the actions of the Ti3Al + TiB2/TiN hard phases and the grain refinement strengthening. Moreover, the wear mass losses of the Ti3Al + TiB2/TiN composite coatings were much lower than that of the substrate. Copyright © 2011 John Wiley & Sons, Ltd